In a stinging rebuke of the Kentucky Republican establishment, tea-party-affiliated Lewis County Judge-Executive Thomas Massie won tonight's GOP primary to replace retiring Rep. Geoff Davis (R) in the 4th district.

With 72 percent of precincts reporting, the Associated Press called the race for Massie. He had 44.9 percent of vote, state Rep. Alecia Webb-Edgington had 29 percent and Boone County Judge-Executive Gary Moore had 17.4 percent.

The district is safe Republican turf, so Massie is almost certain to be a Member of the 113th Congress.

His campaign was given a boost by a half-million-dollar independent expenditure from a Texas-based super PAC reportedly funded by a wealthy college student. But, more than that, the blessing of Paul helped Massie pull out a victory in this northern Kentucky district that one GOP operative described as "tea party central."

Paul, of course, rocketed to national fame when he beat the establishment candidate, Trey Grayson, in the 2010 Senate primary. Senate Minority Leader Mitch McConnell (Ky.) strongly backed Grayson, then the Kentucky secretary of state. But McConnell stayed well clear of the 4th district race this cycle.

This contest was another scrum in the GOP's broader establishment-vs.-tea party fight. Groups such as the powerful pro-free market Club for Growth and FreedomWorks PAC had given their nod to Massie, an MIT grad and successful entrepreneur. Both groups recently won a big contest with the victory of Richard Mourdock over Sen. Dick Lugar in the Indiana GOP primary.

Outside groups spent more than $700,000 on this race, most supporting Massie.

In other Kentucky primary news, attorney Andy Barr easily won the GOP contest to take on Rep. Ben Chandler (D) in the state's 6th district. Chandler has the edge in this rematch. Barr lost to Chandler by only 647 votes in 2010. Roll Call rates that race as Leans Democratic.